The present invention is related to the operation of a wind energy plant with a double-fed asynchronous generator, which has a mode of operation as a phase shifter. In this mode of operation, reactive power is fed into the electric power supply grid by the wind energy plant. The invention is also related to a wind energy plant with a double-fed asynchronous generator which is suited in a particularly high degree for feeding reactive power into the grid.
In a wind energy plant with a double-fed asynchronous generator, the stator is directly connected to the electric power supply grid. The rotor is electrically connected to a converter via slip rings. The converter has to be dimensioned only for the slip power of the generator. The latter is proportional to the rotational speed slip s of the asynchronous generator: wherein nS means the synchronous generator rotational speed and nR the generator's maximum working rotational speed.
A wind energy plant with a double-fed asynchronous generator can feed reactive power into the electric power supply grid under the following conditions: via a grid converter (reactive power support) in the normal active power production operation, via the rotor converter as well as via the generator and/or the grid converter in the normal active power production operation.
The present invention is based on the objective to provide a method for the operation of a double-fed asynchronous generator and to create a wind energy plant with a double-fed asynchronous generator which permits the production of reactive power in a particularly simple manner.